1 /* $OpenBSD: log.c,v 1.50 2017/05/17 01:24:17 djm Exp $ */ 2 /* 3 * Author: Tatu Ylonen <ylo@cs.hut.fi> 4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 5 * All rights reserved 6 * 7 * As far as I am concerned, the code I have written for this software 8 * can be used freely for any purpose. Any derived versions of this 9 * software must be clearly marked as such, and if the derived work is 10 * incompatible with the protocol description in the RFC file, it must be 11 * called by a name other than "ssh" or "Secure Shell". 12 */ 13 /* 14 * Copyright (c) 2000 Markus Friedl. All rights reserved. 15 * 16 * Redistribution and use in source and binary forms, with or without 17 * modification, are permitted provided that the following conditions 18 * are met: 19 * 1. Redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer. 21 * 2. Redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 26 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 27 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 28 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 29 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 30 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 31 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 32 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 33 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 34 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 35 */ 36 37 #include <sys/types.h> 38 39 #include <fcntl.h> 40 #include <stdarg.h> 41 #include <stdio.h> 42 #include <stdlib.h> 43 #include <string.h> 44 #include <syslog.h> 45 #include <unistd.h> 46 #include <errno.h> 47 #include <vis.h> 48 49 #include "log.h" 50 51 static LogLevel log_level = SYSLOG_LEVEL_INFO; 52 static int log_on_stderr = 1; 53 static int log_stderr_fd = STDERR_FILENO; 54 static int log_facility = LOG_AUTH; 55 static char *argv0; 56 static log_handler_fn *log_handler; 57 static void *log_handler_ctx; 58 59 extern char *__progname; 60 61 /* textual representation of log-facilities/levels */ 62 63 static struct { 64 const char *name; 65 SyslogFacility val; 66 } log_facilities[] = { 67 { "DAEMON", SYSLOG_FACILITY_DAEMON }, 68 { "USER", SYSLOG_FACILITY_USER }, 69 { "AUTH", SYSLOG_FACILITY_AUTH }, 70 { "LOCAL0", SYSLOG_FACILITY_LOCAL0 }, 71 { "LOCAL1", SYSLOG_FACILITY_LOCAL1 }, 72 { "LOCAL2", SYSLOG_FACILITY_LOCAL2 }, 73 { "LOCAL3", SYSLOG_FACILITY_LOCAL3 }, 74 { "LOCAL4", SYSLOG_FACILITY_LOCAL4 }, 75 { "LOCAL5", SYSLOG_FACILITY_LOCAL5 }, 76 { "LOCAL6", SYSLOG_FACILITY_LOCAL6 }, 77 { "LOCAL7", SYSLOG_FACILITY_LOCAL7 }, 78 { NULL, SYSLOG_FACILITY_NOT_SET } 79 }; 80 81 static struct { 82 const char *name; 83 LogLevel val; 84 } log_levels[] = 85 { 86 { "QUIET", SYSLOG_LEVEL_QUIET }, 87 { "FATAL", SYSLOG_LEVEL_FATAL }, 88 { "ERROR", SYSLOG_LEVEL_ERROR }, 89 { "INFO", SYSLOG_LEVEL_INFO }, 90 { "VERBOSE", SYSLOG_LEVEL_VERBOSE }, 91 { "DEBUG", SYSLOG_LEVEL_DEBUG1 }, 92 { "DEBUG1", SYSLOG_LEVEL_DEBUG1 }, 93 { "DEBUG2", SYSLOG_LEVEL_DEBUG2 }, 94 { "DEBUG3", SYSLOG_LEVEL_DEBUG3 }, 95 { NULL, SYSLOG_LEVEL_NOT_SET } 96 }; 97 98 SyslogFacility 99 log_facility_number(char *name) 100 { 101 int i; 102 103 if (name != NULL) 104 for (i = 0; log_facilities[i].name; i++) 105 if (strcasecmp(log_facilities[i].name, name) == 0) 106 return log_facilities[i].val; 107 return SYSLOG_FACILITY_NOT_SET; 108 } 109 110 const char * 111 log_facility_name(SyslogFacility facility) 112 { 113 u_int i; 114 115 for (i = 0; log_facilities[i].name; i++) 116 if (log_facilities[i].val == facility) 117 return log_facilities[i].name; 118 return NULL; 119 } 120 121 LogLevel 122 log_level_number(char *name) 123 { 124 int i; 125 126 if (name != NULL) 127 for (i = 0; log_levels[i].name; i++) 128 if (strcasecmp(log_levels[i].name, name) == 0) 129 return log_levels[i].val; 130 return SYSLOG_LEVEL_NOT_SET; 131 } 132 133 const char * 134 log_level_name(LogLevel level) 135 { 136 u_int i; 137 138 for (i = 0; log_levels[i].name != NULL; i++) 139 if (log_levels[i].val == level) 140 return log_levels[i].name; 141 return NULL; 142 } 143 144 /* Error messages that should be logged. */ 145 146 void 147 error(const char *fmt,...) 148 { 149 va_list args; 150 151 va_start(args, fmt); 152 do_log(SYSLOG_LEVEL_ERROR, fmt, args); 153 va_end(args); 154 } 155 156 void 157 sigdie(const char *fmt,...) 158 { 159 va_list args; 160 161 va_start(args, fmt); 162 do_log(SYSLOG_LEVEL_FATAL, fmt, args); 163 va_end(args); 164 _exit(1); 165 } 166 167 void 168 logdie(const char *fmt,...) 169 { 170 va_list args; 171 172 va_start(args, fmt); 173 do_log(SYSLOG_LEVEL_INFO, fmt, args); 174 va_end(args); 175 cleanup_exit(255); 176 } 177 178 /* Log this message (information that usually should go to the log). */ 179 180 void 181 logit(const char *fmt,...) 182 { 183 va_list args; 184 185 va_start(args, fmt); 186 do_log(SYSLOG_LEVEL_INFO, fmt, args); 187 va_end(args); 188 } 189 190 /* More detailed messages (information that does not need to go to the log). */ 191 192 void 193 verbose(const char *fmt,...) 194 { 195 va_list args; 196 197 va_start(args, fmt); 198 do_log(SYSLOG_LEVEL_VERBOSE, fmt, args); 199 va_end(args); 200 } 201 202 /* Debugging messages that should not be logged during normal operation. */ 203 204 void 205 debug(const char *fmt,...) 206 { 207 va_list args; 208 209 va_start(args, fmt); 210 do_log(SYSLOG_LEVEL_DEBUG1, fmt, args); 211 va_end(args); 212 } 213 214 void 215 debug2(const char *fmt,...) 216 { 217 va_list args; 218 219 va_start(args, fmt); 220 do_log(SYSLOG_LEVEL_DEBUG2, fmt, args); 221 va_end(args); 222 } 223 224 void 225 debug3(const char *fmt,...) 226 { 227 va_list args; 228 229 va_start(args, fmt); 230 do_log(SYSLOG_LEVEL_DEBUG3, fmt, args); 231 va_end(args); 232 } 233 234 /* 235 * Initialize the log. 236 */ 237 238 void 239 log_init(char *av0, LogLevel level, SyslogFacility facility, int on_stderr) 240 { 241 argv0 = av0; 242 243 if (log_change_level(level) != 0) { 244 fprintf(stderr, "Unrecognized internal syslog level code %d\n", 245 (int) level); 246 exit(1); 247 } 248 249 log_handler = NULL; 250 log_handler_ctx = NULL; 251 252 log_on_stderr = on_stderr; 253 if (on_stderr) 254 return; 255 256 switch (facility) { 257 case SYSLOG_FACILITY_DAEMON: 258 log_facility = LOG_DAEMON; 259 break; 260 case SYSLOG_FACILITY_USER: 261 log_facility = LOG_USER; 262 break; 263 case SYSLOG_FACILITY_AUTH: 264 log_facility = LOG_AUTH; 265 break; 266 case SYSLOG_FACILITY_LOCAL0: 267 log_facility = LOG_LOCAL0; 268 break; 269 case SYSLOG_FACILITY_LOCAL1: 270 log_facility = LOG_LOCAL1; 271 break; 272 case SYSLOG_FACILITY_LOCAL2: 273 log_facility = LOG_LOCAL2; 274 break; 275 case SYSLOG_FACILITY_LOCAL3: 276 log_facility = LOG_LOCAL3; 277 break; 278 case SYSLOG_FACILITY_LOCAL4: 279 log_facility = LOG_LOCAL4; 280 break; 281 case SYSLOG_FACILITY_LOCAL5: 282 log_facility = LOG_LOCAL5; 283 break; 284 case SYSLOG_FACILITY_LOCAL6: 285 log_facility = LOG_LOCAL6; 286 break; 287 case SYSLOG_FACILITY_LOCAL7: 288 log_facility = LOG_LOCAL7; 289 break; 290 default: 291 fprintf(stderr, 292 "Unrecognized internal syslog facility code %d\n", 293 (int) facility); 294 exit(1); 295 } 296 } 297 298 int 299 log_change_level(LogLevel new_log_level) 300 { 301 /* no-op if log_init has not been called */ 302 if (argv0 == NULL) 303 return 0; 304 305 switch (new_log_level) { 306 case SYSLOG_LEVEL_QUIET: 307 case SYSLOG_LEVEL_FATAL: 308 case SYSLOG_LEVEL_ERROR: 309 case SYSLOG_LEVEL_INFO: 310 case SYSLOG_LEVEL_VERBOSE: 311 case SYSLOG_LEVEL_DEBUG1: 312 case SYSLOG_LEVEL_DEBUG2: 313 case SYSLOG_LEVEL_DEBUG3: 314 log_level = new_log_level; 315 return 0; 316 default: 317 return -1; 318 } 319 } 320 321 int 322 log_is_on_stderr(void) 323 { 324 return log_on_stderr && log_stderr_fd == STDERR_FILENO; 325 } 326 327 /* redirect what would usually get written to stderr to specified file */ 328 void 329 log_redirect_stderr_to(const char *logfile) 330 { 331 int fd; 332 333 if ((fd = open(logfile, O_WRONLY|O_CREAT|O_APPEND, 0600)) == -1) { 334 fprintf(stderr, "Couldn't open logfile %s: %s\n", logfile, 335 strerror(errno)); 336 exit(1); 337 } 338 log_stderr_fd = fd; 339 } 340 341 #define MSGBUFSIZ 1024 342 343 void 344 set_log_handler(log_handler_fn *handler, void *ctx) 345 { 346 log_handler = handler; 347 log_handler_ctx = ctx; 348 } 349 350 void 351 do_log2(LogLevel level, const char *fmt,...) 352 { 353 va_list args; 354 355 va_start(args, fmt); 356 do_log(level, fmt, args); 357 va_end(args); 358 } 359 360 void 361 do_log(LogLevel level, const char *fmt, va_list args) 362 { 363 struct syslog_data sdata = SYSLOG_DATA_INIT; 364 char msgbuf[MSGBUFSIZ]; 365 char fmtbuf[MSGBUFSIZ]; 366 char *txt = NULL; 367 int pri = LOG_INFO; 368 int saved_errno = errno; 369 log_handler_fn *tmp_handler; 370 371 if (level > log_level) 372 return; 373 374 switch (level) { 375 case SYSLOG_LEVEL_FATAL: 376 if (!log_on_stderr) 377 txt = "fatal"; 378 pri = LOG_CRIT; 379 break; 380 case SYSLOG_LEVEL_ERROR: 381 if (!log_on_stderr) 382 txt = "error"; 383 pri = LOG_ERR; 384 break; 385 case SYSLOG_LEVEL_INFO: 386 pri = LOG_INFO; 387 break; 388 case SYSLOG_LEVEL_VERBOSE: 389 pri = LOG_INFO; 390 break; 391 case SYSLOG_LEVEL_DEBUG1: 392 txt = "debug1"; 393 pri = LOG_DEBUG; 394 break; 395 case SYSLOG_LEVEL_DEBUG2: 396 txt = "debug2"; 397 pri = LOG_DEBUG; 398 break; 399 case SYSLOG_LEVEL_DEBUG3: 400 txt = "debug3"; 401 pri = LOG_DEBUG; 402 break; 403 default: 404 txt = "internal error"; 405 pri = LOG_ERR; 406 break; 407 } 408 if (txt != NULL && log_handler == NULL) { 409 snprintf(fmtbuf, sizeof(fmtbuf), "%s: %s", txt, fmt); 410 vsnprintf(msgbuf, sizeof(msgbuf), fmtbuf, args); 411 } else { 412 vsnprintf(msgbuf, sizeof(msgbuf), fmt, args); 413 } 414 strnvis(fmtbuf, msgbuf, sizeof(fmtbuf), VIS_SAFE|VIS_OCTAL); 415 if (log_handler != NULL) { 416 /* Avoid recursion */ 417 tmp_handler = log_handler; 418 log_handler = NULL; 419 tmp_handler(level, fmtbuf, log_handler_ctx); 420 log_handler = tmp_handler; 421 } else if (log_on_stderr) { 422 snprintf(msgbuf, sizeof msgbuf, "%.*s\r\n", 423 (int)sizeof msgbuf - 3, fmtbuf); 424 (void)write(log_stderr_fd, msgbuf, strlen(msgbuf)); 425 } else { 426 openlog_r(argv0 ? argv0 : __progname, LOG_PID, log_facility, &sdata); 427 syslog_r(pri, &sdata, "%.500s", fmtbuf); 428 closelog_r(&sdata); 429 } 430 errno = saved_errno; 431 } 432